Electric heater



FIG. 1 is a front view of a heater in accordance with the invention;

FIG. 2 is a top view of the heater of FIG. 1;

FIG. 3 is a left side view of the heater of FIG. 1;

FIG. 4 is a right side view of the heater of FIG. 1; and,

FIG. 5 is a perspective view of the heater of FIG. 1.

Features shown in broken line, including the grill patterns at the top and front of the heater, the control knobs and indicator light at the top right of the heater, and the power cord at the rear of the heater, form no part of the claimed design. 

The ornamental design for an electric heater, as shown and described. 